In Jenkins 2.11, after uploading a Job, the entities at least in textareas are no longer encoded
Steps to verify:

1) Create a job with e.g. shell code in a build step and some encoded characters (e.g. quotation marks: ")
2) Download the job config via the REST-API
-> quotes are encoded as """
3) re-upload/Replace the same job/data again
4) Download the configuration again & compare with result of step 2)
-> quotes are not encoded
Optional step:
5) Save the job again via the GUI by clicking SAVE
6) Download the cofiguration via the API again and compare with result of step 2)
-> Both download are identical, i.e. the quotes are encoded again

With an account on the server and wireshark we could verify that the configuration is sent/uploaded correctly (=encoded) to the server in step 3), but stored unencoded on the serversin the local XML. This is corrected after savig again in step 5)